research methods
Card sorting
What is card sorting?
Card sorting is a research method where users group labelled cards into categories that feel natural to them. It shows how they mentally organise information - the raw material for an information architecture built on their logic, not yours.
Also known as: card sort, content sorting
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The demo
Nine things a user might want to do, all jumbled. Click a card to move it into a group - Account, Billing or Support - and watch a structure take shape. Click again to keep cycling if it doesn't feel right.
Click each card to sort it into the group where you'd expect to find it.
What this demo shows (text version)
Nine task cards - reset password, update card, request a refund, change email, download an invoice, contact us, close account, view billing history, report a bug - start unsorted. Clicking a card moves it into one of three groups (Account, Billing, Support), and clicking again cycles it on, so you can sort everything by clicking rather than dragging.
A counter shows how many cards remain unsorted. As the cards settle into groups, an information architecture emerges from your own sense of where each item belongs - which is exactly what a card sort captures when run with real users: their grouping logic, ready to base a navigation on.
Card sorting lets users group labelled cards into categories that feel natural to them, revealing their mental filing system. Build your information architecture from the patterns across many sorts rather than your own assumptions - the structure will match how users actually expect to find things. You can see and try this concept in action on this page.
You just sorted nine scattered items into a handful of groups - and the moment they clicked into place, an information architecture started to form. Do that with real users instead of guessing, and you get categories people can actually predict, because they are the ones who drew the lines.
Two flavours. Open card sorting lets people name their own groups - best early, when you want to discover how users carve up the space. Closed card sorting gives them your categories and asks them to file cards into them - best later, to test whether a structure you already have actually works. Run open to learn, closed to check.
The gold is in the disagreements. Where everyone sorts the same way, you have an easy call; where they split, you have found a genuinely ambiguous item that needs a clearer label or a cross-link, not a coin toss. Look for the cards that refuse to sit still - those are the ones your navigation will trip over. Pairs naturally with [information architecture](/entries/information-architecture/).